Bug 20665 – std.concurrency.spawn should document not working with delegates

std.concurrency.spawn only accepts function pointers and callable types without mutable aliasing as its first argument. A logical thing for a user to attempt is to use a delegate, like e.g. this: struct S { void fun() {} void gun() { import std.concurrency; spawn(&fun); // Won't compile } } This will not compile, with a somewhat confusing error message about "cannot deduce function from argument types". There should be an overload like this: void spawn(F, T...)(F fn, T args) if (isDelegate!F) { static assert(false, "Delegates can hold aliases to mutable state."); } In addition, the documentation should mention that this is a limitation, and why (delegate contexts have no constness, and so may alias mutable state).

@Biotronic created dlang/phobos pull request #7506 "Fix issue 20665 - std.concurrency.spawn should document not working with delegates" mentioning this issue: - Fix issue 20665 https://github.com/dlang/phobos/pull/7506

dlang/phobos pull request #7506 "Fix issue 20665 - std.concurrency.spawn should document not working with delegates" was merged into master: - abb2156487b7d7015cd8f059b1083297cfbee06b by Biotronic: Fix issue 20665 - 69800d947552c198f6745564ada72d624b6ffe90 by RazvanN7: Fix Issue 20665 - std.concurrency.spawn should document not working with delegates https://github.com/dlang/phobos/pull/7506